1. Field of the Invention
The present invention relates to an optical pickup device used for recording and reproducing information on a high density recording disk such as a DVD and information on a low density recording disk such as a compact disk and the like. More particularly, the present invention relates to an optical pickup device in which a tilt caused by a lens shift is self-canceled so that a radial tilt can be conducted. The present invention also relates to an optical disk device on which the optical pickup device is mounted.
2. Description of the Related Art
In the case of a conventional optical pickup device, it has been known that an objective lens is inclined, which is referred to as a tilt hereinafter, due to the structure of a magnetic circuit when a focusing motion and a tracking motion are simultaneously conducted which is referred to as a lens shift hereinafter. In order to prevent the occurrence of the above problems, there is proposed an optical pickup device in which the structure of the magnetic circuit is devised so that no tilt is caused even when the lens is shifted. For example, refer to JP-A-10-031829 (pages 3 to 4, FIGS. 4, 5 and 6).
Since the high density recording disk such as a DVD has widely spread, there is a demand for an optical disk device by which information on the high density recording disk can be reproduced and recorded in the same manner as that of the conventional optical disk device for recording and reproducing information on the low density recording disk.
However, in the case of the high density recording disk, the recording density is so high that the tolerance (tilt margin) with respect to an inclination angle of the objective lens is far narrow. Therefore, it is demanded to the optical disk device that reproducing and recording can be conducted even when the optical disk is warped.